‘I had a call to make. When I took up the receiver my wife was talking on the extension in her room. She said, “All right, Fred – half past ten or a quarter to eleven,” and then she rang off. So you see, I knew that she was meeting Worple, but I didn’t know where. At a quarter to ten I went into the drawing-room and told her I was going to bed.’

‘You have separate rooms?’

‘Oh, yes.’

‘Next to each other?’

He shook his head.

‘It’s a big house. It’s been in the family a long time. I have the room I used to have when I came to stay as a boy. My wife’s room is at the other end of the house.’

‘Well, you went to bed?’

He shook his head.

‘No, I went to my room and waited. One of my windows overlooks the side door. I thought if my wife was going out, or if she was letting anyone in, that she would use this door. The front door bolts make quite a noise when they are drawn back. So I put out my light and sat by the window and waited. I went on waiting and nothing happened. I thought I wouldn’t do anything until a quarter past eleven, and that then I would go along to my wife’s room and see whether she was there, because there were two other doors which she might have gone out by. My watch has luminous hands. At twenty past eleven my wife came out of the side door and went on round the house and out of sight. I was all ready to follow her in a dark raincoat and tennis shoes. It takes just five minutes to walk from Grove Hill House to The Lodge. I want to make it clear that I could see my wife in front of me all the way. When I turned the corner into Hill Rise she was standing still – in fact I very nearly ran into her. On the other side of the road a woman was running down to the corner, and the bus was coming down Belview Road. When it came to the corner by The Lodge it stopped and the woman got in. I was only about three yards away from my wife. As soon as the bus had gone she ran the rest of the way and went in by the tradesmen’s entrance of The Lodge. It is right on the corner and runs along by the hedge to the little yard outside the back door. As soon as she turned in like that I guessed that she had been meeting this man Worple in that kind of a summerhouse at the top of the Grahams’ garden. They call it a gazebo. Of course you will have seen it, because that is where Mrs Graham’s body was found. I don’t know why she went there. She always goes to bed very early. I let my wife get round the house, and then I followed her. When I came out on to the path that goes up the garden I could see her ahead of me. I want you to be quite clear that except while I was following her round the house she was never out of my sight. Is that quite clear?’

Inspector Sharp nodded and said, ‘Oh, yes, Mr Harrison.’

Jack Harrison went on in the same precise and methodical manner which he had used throughout.

‘I could see her, partly because I was looking for her, and partly because I have very good night vision. Neither she nor any other person could or did see me, because by the time they were heading my way I was standing still against a dark background.’

Frank Abbott said sharply,

‘The other person? What other person?’

Jack Harrison looked faintly surprised.

‘There was a man in the gazebo. As you know, there are steps going up to it. When my wife had reached the top step, a man rushed past her, knocking her down.’

‘Do you mean that he hit her?’

‘Oh, no, I don’t think so. He was just in a hurry to get away.’

‘Mrs Harrison must know whether he hit her.’

The surprise became more apparent.

‘I haven’t spoken about it to my wife. She has no idea that I was there.’

‘All right, go on.’

He did so in a meditative tone.

‘If she lost a stone out of her ring as you say she did, then I think it must have happened when she fell. Her hand could have struck the jamb.’

‘Very likely. But go on about the man.’

‘He came running down the path very fast. I stepped into a garden bed to avoid him. There is a little step down to the yard outside the back door. He must have forgotten it, because he tripped and came down sprawling. He was up again in a moment and ran round the house and away.’

‘Did you recognize him?’

Jack Harrison shook his head.

‘Not in the way of seeing his face. But it wasn’t Mr Worple.’

‘How do you know it wasn’t?’

‘He wasn’t tall enough. Mr Worple must be not far off six foot. As this man went past me be was not much taller than myself, but there was a good deal more of him. Not a tall man, but broad. A heavy man by the way he fell.’

Miss Silver had said nothing all this time. She listened, and she watched with keen attention. She did not herself feel any difficulty in identifying the man who was broad but not tall, and who fell heavily, with Mr Blount.

Frank Abbott said,

‘What happened after that?’

Jack Harrison replied in the simplest manner.

‘He got up again.’

‘You did not try to stop him?’

‘I had no reason to do so. It was not until next day that I had any reason to suspect that he had probably murdered Mrs Graham.’

Frank Abbott said,

‘Well go on. He got up…’

‘And rushed away. My wife was getting to her feet at the entrance to the gazebo. If she was expecting to meet Mr Worple, and I think there is no doubt that she was, it must have been a great shock to be knocked down by a violent stranger. She came limping down the path towards me, breathing in a distressed manner. I stood perfectly still behind a clump of hollyhocks and let her go by.’

Frank Abbott leaned forward across the polished table.

‘Did she go into the gazebo?’

Jack Harrison shook his head.

‘Oh, no – she hadn’t a chance – she was knocked down on the threshold.’

‘But afterwards – when she got up again?’

‘Oh, no. She was groaning and getting up – I could hear her all the time. I think her one idea was to get away. She came down the steps and down the path and went round the house and out into the road. And then she went home.’

‘You’re sure about that?’

‘I followed her. When she got inside the drive she stood for a bit. There is a path that goes off to the left through a shrubbery. I went that way because I wanted to get in first. I had some thoughts of locking her out, but I considered that she had been very badly frightened, and that it would be a cruel thing to do, so I just went up to my room and left the door unlocked.’

‘You are sure she came in?’

‘Oh, yes. I waited by the window until I saw her come round the house and go in. I had set my door ajar, and I heard her come up the stairs and go away to her own room.’

‘You didn’t speak to her about what had happened, either then or next day?’

‘No.’

‘Why didn’t you?’

‘I didn’t wish to have a scene with my wife.’

Having been privileged to witness one of these conjugal scenes, the two Inspectors believed him. Frank Abbot said,

‘You said nothing to her at all even when you had heard about Mrs Graham’s murder?’

‘No, I didn’t say anything.’

‘Mr Harrison, you must have realized the importance of your encounter with this man on the scene of the murder. He was at any rate an intruder upon private property, and his behaviour is, to say the least of it, highly suspicious. He hasn’t any business in the gazebo. He knocks a woman down and makes a bolt for it when he is discovered there. You must surely have realized that it was your duty to go to the police?’

‘Oh, yes. But you see my wife was involved.’

Frank Abbott’s light, cool gaze rested upon him.

‘We have a witness who heard Mrs Graham speaking to someone in the gazebo at just after twenty past eleven. This witness was frightened and ran down to the corner to catch the bus. If, as you say, the bus was at the corner and a woman was running down towards it when you turned into Hill Rise, this witness’s statement is confirmed, and it becomes clear that Mrs Graham was murdered between the time when she was heard to call out and the moment when you saw this man whom you have described rush out of the gazebo.’